Method of making cyanids.



No. 686,949. Patented Nov. I9, |901. J. PFLEGER.

METHOD 0F MAKlNG CYANIDS.

(Application filed Mar. l5, 1901.)

(No Model.)

l JWM INITEE STATES PATENT OFFICE.

.OHANNESV'PFLEGER, OF FRANKFORTON-THE-MAIN, GERMANY, ASSIGNOR TO THE FIRM OF DEUTSCHE GOLD 8a SILBER-SCHEIDE AN'STALT, VORM. ROESSLER, OF FRANKFORT-ONgTHElMAlN, GERMANY.

Msi-Honor MAKING oYANlofs.

SPEGIFIGAITI'MW forming part of Letters Patent No. 686,949, dated November 19, 1901.

l Application filed March 145, 1901, Serial Nof 51,416. (N0 specimens.)

To all whom it' may concern:

Be it known that I, JOHANNES'PFLEGER, a subject of the Emperor of Germany, and a resident of 215 Gutleutstrasse,.Frankfort-on- 5 the-Main, Germany, have invented certain new and useful Improvements in the Manufacture of Alkali Oyanids, of which the'following is a specification.

, In the specification of my application for 1o Letters Patent, Serial No. 39,382, dated December 10, 1900, a process is described by which the synthesis of alkali cyanide is effected from an alkali metal, ammonia, and carbon by transforming the alkali amid, 15 which is easily decomposable at a high temperature, into the corresponding remarkably stable cyanamid by adding to it, as it forms a calculated quantity of cyanid, and converting the said L :yanamid into cyanid by 2o combination with a further equivalent of carbon while the temperature is raised. f Further tests made by me have shown that the intermediate formation of the cyanamid and a better utilization of the alkali metal and ain- 25 monia can be eEected in an improved manner. I have discovered that cyanamid can also be formed directly from the amid of the alkali metal and carbon if the temperature of the reacting mixture be maintained at a point 3o not exceeding the temperature at which the amide of the alkali metal decomposes.

The formation of cyanamid from alkali amid and carbon according to the formula:

commences at 350 centigrade and is a vmost powerful one at 400 centigrade.

The object of the invention described in the specification of the aforesaid application 4o lfor Letters Patent is to transform immediately into cyanamid the sodiin amid obtained by the combination of sodium and ammonia, so as to protect it from decomposition,

Y as the said sodium amid is easily decom- 45 posed at the temperature required for the formation of cyanid. The same object is attained according to the present invention by4 omitting wholly or in part the addition of cyanid recommended in the specification of 5o the said prior application and keeping the temperature of the Iirst part of -the processen `low that no cyanid is formed, but the whole of the sodium amid is at the moment of its formation converted into cyanamid by the carbon present. `While this cyanamid isin the course of formation the temperature must be raised slowly to the higher melting-point ofy this body and brought finally to about 600 centigrade. Unlike that which takes place in the direct formation of cyanid, which requires ,a much higher temperature, the temperature at which the cyanamid` is formed according to this invention does not involve any important loss through the decomposition of alkali amid. It is only after the whole of the sodium is converted into cyanamid, and thus protected against losses, that the temperature is so raised as to eect its conversion into cyanid according to Drechsele well-known reaction Name+-022mm.

Instead of solid carbon-such, for example, as charcoal-other carbonaceous substances which contain carbon mechanically or chemically combined and are capable of giving i1 up as required by the above reactions may be used. For instance, liquid or gaseous hydrocarbons may be introduced into the molten sodium through the same inlet as the ammoniaA or through a separate inlet.

The accompanying drawing shows a melting vessel in sectional elevation, in which m5 process may be carried out.

In the drawing, a. is the vessel, b the charging-opening, and c the tube, which may be used for passing ammonia into the vessel..

I claim- 1. The process herein described of making alkali cyanids, lwhich consists in iirst reacting alkali metal with carbon and ammonia in proportions necessary for the formation of alkali cyanamid,while maintaining the temperature of the mass at about 350 to`600 centigrade, and then reacting the 'produced cyanamid with a further. quantity of carbon at a highel temperature, ,whereby cyanid is formed, as

and for the purpose set forth.

, 2. The process herein described of making alkali cyanide, which consists in rst reacting alkali metal with Huid carbon compounds and ammonia while maintaining the temperature of the mass at about 350 to 600 centigrade,

whereby alkali cyauamid is formed, and re- 5 acting the produced cyanamid with a further 4. The process herein described of making alkali cyanids, which consists in first reacting alkali metal with carbonaceous substances and ammonia while maintaining the temperature at about 350 to 600 centigrade, whereby cyanamid is formed, and then reacting the produced cyanamid with a furtherquantity of carbonaceous substances at a temperature of substantially 750 to 800 centigrade,where by cyanid is formed, as and for the purpose -set forth.

' In testimony whereof I have signed my 3 name to this specification in the presence of two subscribing witnesses. JOHANNES PFLEGER. Witnesses:

JEAN GRUND, CARL GRUND. 

